1. Field of the Invention
The invention concerns an electric capacitor with two electrode units each of which consists of a plurality of capacitor plates having paired mutually opposite surfaces, and where each plate has two mutually opposite lateral edges. One of these edges is free while the other is joined to a carrier or support and is so held by the latter that a gap is formed between the mutually oppositely positioned surfaces of the plates of each electrode unit, this gap being greater than the thickness of the plates of the other electrode unit. Further, the plates of one electrode unit extend into the gaps between the plates of the other electrode unit. In order to vary the depth of extension of the plates into the gap between these plates all such plates of both electrode units are arranged in parallel with a straight line along which their mutual position can be set.
2. Description of the Prior Art
In known capacitors of the type described above, the electrode units consist of several planar or cylindrical capacitor plates, as described e.g. in British patent specification No. 1 277 341.
There are also, however, capacitors of the above-mentioned type wherein each electrode unit consists of a single band-shaped capacitor plate which is wound into a spiral and the turns of such capacitor plates of one electrode unit are disposed in the gap between the turns of the capacitor plate of the other electrode unit, as shown e.g. in U.S. Pat. No. 1,590,678 or 3,284,682.
In each of these known cases the exact alignment of the capacitor plates, or of the turns of the capacitor plates of one electrode unit in relation to the plates or turns of the plate of the other electrode unit presents certain difficulties. Ideally, the plates or rather, the turns of the plate of one electrode unit ought to be positioned exactly in the middle of the gaps between the plates or turns of the plates of the other electrode unit; in practice, this is seldom possible.